Job done! Australia win Ashes 4-0

AUSTRALIA are 4-0 Ashes champions after Pat Cummins cleaned up a mentally and physically fried England at the SCG.

Joe Root battled bravely through a viral stomach bug that had him in hospital early this morning, but he was unable to continue after lunch and Australia struck immediately to polish off the nine wickets required to end the job.

In the end it was a landslide innings and 123-run triumph for Australia, with Cummins taking four scalps to finish leading wicket-taker (23) for the series.

It is a huge victory for Australia's bowling unit who have all finished the series with 20 wickets apiece to completely dominate their opponents from start to finish.

England resumed day five's fight for survival four wickets down, but Moeen Ali was forced to come out for the opening exchanges with Jonny Bairstow as Root tried desperately to recover in the dressing rooms.

The late change presented a crack for Australia to exploit and spinner Nathan Lyon wasted no time in knocking over Moeen for a remarkable seventh times in nine innings this Ashes series.

Australian captain Steve Smith holds a replica Ashes urn after Australia wrapped up the series with victory over England at the SCG on Monday.

Lyon trapped Moeen lbw, and the opposing spinner didn't even contemplate a review as he trudged off the field, the end of a dismal campaign for arguably England's biggest underperformer.

Root and Bairstow held firm until lunch with a stoic stand, but during the interval the England skipper suffered a return of the symptoms that had demanded urgent medical attention in the morning.

England confirmed that Root's illness had nothing to do with yesterday's 57.1 degree heat in Sydney, and was a viral gastro bug that had him up all night vomiting and dehydrated and with diarrhea.

Root retired ill on 58 and despite his courage, when he failed to return from lunch England were always on borrowed time.

Within minutes Bairstow (38) was trapped lbw, and then Cummins pace and bounce was far too menacing for tail enders Stuart Broad and Mason Crane to handle.

The final wicket went to Josh Hazlewood in bizarre circumstances, with James Anderson adamant he didn't nick the ball, but with no reviews to challenge with.